Officers are using their broad powers of inspection for searches that may result in criminal proceedings. This is where they get away with it, and we as citizens, allow them to.
Courts have found that if you chose to participate in a regulated activity (ie hunting, fishing, trapping), you are allowed to be inspected while carrying out those activities. Not all charter rights apply if you choose to participate. A good example of how powers of inspectors that we are all familiar with is a health inspector at a restaurant. The restaurant cannot say no to the inspection because by choosing to participate in a regulated activity (serving food for money), they must accept government bodies inspecting their actions. That being said, a health inspector does not have the powers and authority of a peace officer. They can't arrest, and can't lay criminal charges.
Co officers on the other hand have the authority to inspect those who chose to participate in regulated activities (hunting fishing trapping), but then use the information gathered by the inspection for criminal law enforcement. This is the big no no that they aren't allowed to do (without some in between steps). Unfortunately, we let it happen all the time. DFO knows this is an issue, and has lost a significant court case in Saskatchewan over it, and it is why they have generally directed their officers not to participate in highwany road checks. DFO has viewed highway road checks as basically arbitrary detentions/unlawful searches. Courts have found that road checks on highways are allowed for two reasons only. To check for safe vehicle condition and operator impairment. All other purposes are considered arbitrary detention/unlawful searches. But that is a story for another day.
Lets run a scenario and see if I can make better sense that way. To keep the public highway aspect from mixing things up, let's keep this to logging roads and areas where fish and wildlife are normally found. Also, let's focus only on his powers under the federal fisheries act, provincial wildlife act and provincial firearms act. Lets not muddy the waters further with motor vehicle act/forestry and range act stuff
you are driving out of a logging road with a bare truck (empty). You have a canopy and back seat, but it's just you when you come to a co road check. Using his powers of inspection vested under the various acts, the co is allowed to ask you a version of this "are you transporting any fish, wildlife or firearms, or have you been doing any fishing or hunting today". Guess what, if you have chosen to participate in one of those regulated activities, you must answer truthfully. Fail to answer is obstruction of an officer.
if you have not done any of those things, and answer no, you should be free to leave. Now an overzealous officer might find some reason he wants to search further, and without some "reasonable suspicion" that you have been participating in a regulated activity, he is not allowed.
the crux of inspecting further is the reasonable suspicion that you have been participating in a regulated activity. How does that burden get achieved. It is all in what is visible, where you are, and how it is articulated. Some things are easy - fishing rod visible? Prepare to get inspected. Moose hair and blood on tailgate with a tarped object, you are going to be inspected. Does a cooler in the back make reasonable suspicion - I would argue no, coolers carry a lot of things and just having a cooler does not mean I have participated in a regulated activity. In fact, that is what the DFO case in Saskatchewan focused on - a cooler. Does a camper on the truck mean I am subject to further inspection. Again, I would argue no. And this is where we as citizens allow our rights to be eroded. Co can't stop and search every vehicle coming down a logging road. Yet they seem to, and we let them. Why? Probably because their is no recourse on the side of a logging road, and resisting or saying no may set you up for further troubles. Our only resolution is a civil claim in terms of charter infringement or formal complaint against the officer which does not resolve things at all at the time.
So say you have been particpating in a regulated activity, and you answer yes to the initial question. Now the officer has a wide open door to inspect you for compliance with legislation. This means checking your licence to ensure it is valid and in your name, inspecting your firearm and ammunition to ensure it is unloaded and legal, and inspection any fish or wildlife to ensure it is the appropriate numbers, species and size. These are all under the guise of inspection.
Now what happens if during his inspection, he finds something wrong? This is when he now has to where a peace officer hat and do everything right by the courts. If he finds something wrong, the inspection is over, and it is now an investigation. Anything he does further has to comply with the charter of rights. He cannot continue inspecting as that falls into a "search" once he knows there has been a violation. The appropriate way to do things is to place you under arrest or detention for the violation he found, and continue the search as incidental to lawful arrest. In reality, this is rarely done as that means everything stops until you get your lawyer call. They don't want the headache of this so continue as if using their inspection powers. At this point though, anything further found will get tossed in court as "fruit from the poison tree" if they did not do all the appropriate steps for arrest and detention. They could also chose to end the inspection at the time they find the violation, issue you a ticket and send you on your way. No arrest needed as they are not continuing to search and basic ticket issuance time is not viewed as arbitrary detention (thinking of speeding tickets).
so what can an officer look in when he is inspecting? Again, it has got to be reasonable for the issues at hand. You are coming back from moose hunting with a moose in the back and you have given him your licence. He can't go search your glovebox as it would be an arbitrary search that's has nothing to do with the inspection at hand.
At the end of the day, if you have not been particpating in regulated activities, then they have no ability to inspect and thereby search. Many are probably aware of officers who have pushed this boundary just because you were out for a drive on a logging road. Additionally, there may be some instances when you are particpating in regulated activities, where the powers of inspection have been taken too far and stray into the realm of arbitrary search.
so that is roughly how things go. My learnings out of this - don't let the government regulate anything else (ie licence for mushroom picking), keep everything clean and out of site, and don't speak unless I am required. When asked if I have been doing any hunting, fishing or transporting wildlife/firearms, I will listen carefully to what is asked and consider my response appropriately.